APPENDIX. 397 



Rostrum a little longer than the cell, scarcely connected 

 with the rachis^ slender^ and closely adprcssed and adnate 

 to the cell below, wide and projecting upwards ; lateral 

 processes large, rising above the margin of the cell, coni- 

 cal, tubular, or canalicular. 



Hab. — Prince of "Wales Channel, Torres Strait, in 9 

 fathoms. 



Colour of rachis and pinnules, deUcate yellowish white 

 above; of rachis, light brown, inferiorly; poh-pidom 

 about two inches high, rising in several straight simply 

 pinnulated fronds from a common centre ; pinnules ascend- 

 ing about } inch. 



4. P. aiirita, n. sp. 



Cells cup-shaped, tapering at bottom, constricted just 

 below the top ; mouth at an angle of 45°, cii'cular ; margin 

 subcrenate, plicate, with three folds on each side, with a 

 wide shallow notch in front and entire behind. Rostrum, 

 slender, attenuated below, adnate up to the cell, summit 

 contracted, tubular; lateral processes very long, expanding, 

 rising far above the margin of the cell, conical, tubular. 



Hab. — Off Cumberland Isles, 27 fathoms. 



Colour bright brown ; poh^^idom 2 — 3 inches liigh, con- 

 sisting of straight pinnate fr'onds, pinnse or branches not 

 opposite, nor regularly alternate, divaricate at right-angles. 



5. P. hrevirostriSj n. sp. 



Cell sub-tubular, cmwed; mouth expanded with two 

 equal acute teeth on each side, and a longer narrow 

 and slightly incurved, central one in front. Rostrum 

 small, conical, projecting, about half the length of the cell; 

 lateral processes small, recm-ved at an angle, canalicular. 



Hab. — Off Cumberland Isles, 27 fathoms. 



Colom- dirty white. In habit, and to the naked eye, very 

 much like the last; its growth, however, appears to be 

 longer and less regular. The difference in the cell is 

 very great. 



